*** LAST UPDATE 4/14/2024 ***
This is intended to help people who want to build lightweight rifles and/or want to lighten up an existing rifle. This is not necessarily intended to be a comprehensive list, as it only includes parts that are lightweight or nearly so.

RAW DATA SPREADSHEET HERE, v1.03

An updated Parts Database made by another user is here:  
Check this Google Doc
It may be more complete / more updated.

My recommended cheap / light build if you only want to get under 5 lbs for ~ $1k.


For a little more money (about $150 more) you can save a few more ounces


Key:
U = User Data
M = Manufacturer
C = Calculated

Weights listed are in ounces.

Parts in purple are amongst the lightest options


****Upper Parts****
Muzzle Devices
A2 Flash Hider       2.15 U
A2 Extended
Mag Tactical             1.90 M
BE Meyers               2.50 M
AAC Brakeout 51t   4.20 M
AAC Blackout 51t   4.30 M
VDI Manimal            1.48 M
Rainier Mini-Comp    1.44 U
ALG Single Chamber Brake 2.01 U
V7 Titanium   1.35 M
V7 Ti V-grooved  1.25 M
Venom Defense hybrid steel muzzle brake 1.48 U

Charging Handles
PSA Milspec  1.13 U
Breek Arms Warhammer 1.0 U
Spikes Milspec 1.07 U
Rainier Raptor 1.42 U
BCM Gunfighter Med   1.24 U
BCM Gunfighter Small
V7 Ultra-light charging handle  1.04 M

Bolt Carrier Groups
LMT Semi-Auto 11.14 U
Umbrella Corp Full-Auto 11.46 U
RRA Semi-Auto 11.26 U
Spikes NIB FA 11.8 U
Colt F/A BCG 11.56 U
BCM F/A BCG 11.64 U
PSA F/A BCG 11.50 U
Red X Arms Ti 7.81 M
JP LMOS Bolt Carrier 6.25 M
JP Bolt Carrier (full mass) 8.5 M
Young Man. SLC carrier   7.1 U
FN Bolt Only 1.5 U
Smith Aluminum carrier w/ key 3.7 U
PM&T Ti carrier w/ key 5.1 U
V7 Systems Ti Carrier  5.7 M
V7 Systems Ti BCG  7.9 M
DSA Low-Mass Steel BCG 9.1 M
DSA Aluminum BCG 5.2 M
OdinWorks Low Mass BCG (steel) 9.0 MU
WDR Titanium BCG  7.8 M
FosTecH LOW MASS BCG (Nickel Boron) 8.5 M

Gas Blocks
Aero precision 0.625 adjustable
BCM 0.75"  1.30 U
BCM 0.625" 1.928 U
Daniel Def LPGB 0.750        1.28 M
Daniel Def LPGB 0.625        1.92 M
V7 Systems Ti LPGB 0.750  0.74 M
V7 Systems Ti LPGB 0.625  0.71 M
2A Armament Ti 0.750   0.70 M
VLTOR 0.625" (set screw)  1.4 M
Parallax Tactical LPGB          1.47 U
SA 0.75" adjustable 1.8 U
Samson MFG lite 0.625"  0.6 U
YHM LP w/ set screws 1.43 U

Gas Tubes
Del-ton Carbine 0.63 U
Carbine Length  0.7 C
BCM Midlength 0.757 U
V7 Midlength 0.94 U
Mid Length  0.8 U
Rifle Length 0.9 U

Dust Covers
Dust Cover Assembly  0.75 U
Dust Cover Ass., V7   0.37 M
Mako Poly Dust Cover: 0.2 (discontinued?)
UBCM Dust Cover 0.506 U
BCM Dust Cover Pin 0.211 U
BCM Dust Cover Spring 0.021 U
Strike Industries Ultimate Polymer  0.3 M
Strike Industries Ultimate overmolded Polymer 0.5 M
Strike Industries Polyflex  0.3 M
Magpul Polymer   ?

Forward Assists
BCM Forward Assist 0.712 U
BCM FA Spring 0.058 U
WOA Forward Assist Assy  0.74 U
Northtech Ti Forward Assist 0.501 U
Northtech Ti FA Spring 0.050 U
Schuster Mfg FA plug  0.10 U

Upper Receivers
2A Armament Balios Lite stripped, no FA  5.8 M
Aero Precision Forged Stripped 7.16 U
Aero Precision Forged Stripped; no FA   6.4 U
Fostec FLITE Elite Stripped 5.92 M
Kaiser X-7 Poly Upper: 5.5 M
Mega Arms forged stripped 6.9 M
Mega Arms Billet Upper, 9.4 M
Rainier Forged, Complete  8.6 M
Rainier Arms Forged Stripped 7.08 U
Spikes Forged complete: 8.4 U
V7 Weapon Systems Forged Complete 7.7 M
V7 Weapon Systems Forged stripped 6.8 M
V7 Weapon Systems Enlightened 6.0 M
V7 Weapon Systems Enlightened (lithium/aluminum) 5.8 M
Forged no FA, complete  7.3 C

For my lightweight build, I use Breek Arms Warhammer Ambi Charging Handle. The manufacturer claims it's under 1 oz, and I measured mine to be 0.95 oz. So it is true to claim. My normal go to charging handle is the BCM Gunfighter which is about 1.2 oz. Haven't shot my lightweight build much yet, so can't say if the Breek Arms one will be as durable as my BCM ones.

I see Smoke Composite now has anti-tilt lips on their buffer tubes and can now do custom length tubes. I need a custom length tube for my POF Rogue. Does anyone know how well the CF 30-50 holds up compared to 7075?

I also wanted to add that. . .
- Break Arms CH is a complete steal, especially for the feature. Can't beat $50ish

- Tegra Arms does not appear to be around BUT it appears Unbranded AR is making a 'carbon fiber lower'. I've seen a little (not a lot of bad) of good things people have said about Unbranded.  Believe it or not, my Tegra Arms lower has not broken on a suppressed 10.5" BRN180. I wouldn't assume it would anyways given that the end piece to the recoil system is polymer. I was looking for another TA lower for a 22lr dedicated and came across these guys.

With the above being said, does anyone make a good polymer or CF stripped upper that doesn't explode for 22lr?

Am seeing the Tegra "carbon fiber" plastic lowers @ gunshows locally for over $100.  It's just a run of the mill plastic lower w/ carbon fibers mixed into the plastic - so slightly lighter than a nylon fiber reinforced plastic, but no stronger, and potentially weaker.

I'ved used a hybrid poly/steel upper for the boy's left-eject .22 LR AR, but have been told the steel insert brings the weight up to the same mass as an aluminum.  I choose it b/c it was easy to cut the left ejection port.

FYI: DSA sand cut BCGs are back in stock. Just got the notification email. Get em while they're hot!

Got my sand cut. Cheapo scale says 5.25oz.

Thanks. Just got my Unbranded Carbon fiber lower.  It's certainly the same exact design as the Tegra, which I'm assuming was a license or they bought Tegra. I know because my BRN180 has a Tegra lower. Comparing them, besides the logo, it is the same. I'm gonna put this other one on a dedicated 22lr build.

That's good to know. Any time this kind of thing changes hands, it's good to check weights. What does the unbranded one come in at?

3.6 oz.

They have a deal right now until EOD today SITEWIDE20 to get 20% off.

The Hera thumbhole stock is the lightest available thumbhole that will reinforce the lower, and there's some weight you can take out of it, particularly if you're willing to glue it together or use aluminum screws.  16 oz w/ more than a dozen screws.  I've run it w/ one of the polymer buffer tubes.  The ergonomics aren't ideal for the AR safety, but you can make it work.

https://www.thefirearmblog.com/blog/2018/07/13/thumbhole-stocks/

I much prefer the Vism thumbhole for polymer lowers, @ 17.6 oz, but it is shorter and feels much denser - since it is mostly solid, unlike Hera's hollow shell.  You could take weight out of the Vism as well just by drilling holes.

Not a fan of those type of lowers, but I appreciate it. So far, with a suppressed shorty BRN180, I have had 0 issues with the Tegra. I don't think I'll have an issue with it either because the "buffer" retainer at the end of the recoil system is nylon. I wouldn't trust it in a normal 556 lower however.

Holy S. 3 of these undbranded lowers for under $94 shipped with the coupon code? I wasn't planning on buying for a while, but that's a deal that's too good to pass up. Thanks for posting @ahrion

Hey guys, dumb question of the day: if you wanted to run a pistol length gas system on a 14.5" bbl, and you had an adjustable gas key, what size gas port would you run?

Yes, I realize pistol length is far from ideal. If I'm going to have a custom bbl made anyway, I'm exploring all possibilities and a short gas system certainly has weight advantages...

I'm gonna question that assumption - pistol gas systems typically run heavier buffers to slow down the system from the higher pressure gas & earlier unlocking.

I would bet you'll end up w/ a lighter gun running carbine or even mid-gas (if you don't need a bayonet lug) on a 14.5".

If you insist on pistol gas, I'd start off w/ a small gas port, b/c you can always drill it larger if needed.

Oh, I don't mean functional advantages, I meant weight advantages. shorter gas tube, shorter handguard etc.  But yeah, if a heavier buffer would be needed no matter how much you perfected gas port / gas key settings there'd be no point.

I think you'll be ripping rims off brass w/ pistol gas chasing the same weight in a carbine or mid-gas.  If you don't have a bayonet lug, there's no need to cover the gas tube.  The top rail is there to keep you from burning your hand - if you're not stabbing anyone w/ a bayonet, you don't need to cover it.

Magwell grip, no handguard required.

I’d be happy to see a ULW 14.5 pencil barrel in carbine length. I modified a 10.5 with an aluminum p/w extension for a barrel weight of 16.7 oz. but it’s not ideal.

Picked up my 3 Unbranded AR lowers. Weight is 3.65-3.70 per. Same as Tegra back in the day. Cool beans.

Still trying to keep this thread going but. . .

This gas block should be illegal https://airbornearmsllc.com/airborne-arms-shop/gas-blocks/. Wish it were adjustable. 0.83 oz steel and .48 oz Titanium. Insanity.

Just imagine how light it would be if they made one for .625.
Not just .750

Yeah, anyone that wants to build an ultra light would want a thin bbl profile / gas journal.  It's a cool design though and a 625 sized one might top the charts on the PWD.

I would bet money it would.

Best adjustable titanium gas block I've found ever is the Zenitco gas block. The adjustment screw's detent is outside of where the gas touches, so it will never be mucked up. And it has 15 adjustment points with pretty good clicks.  It does use a straight gas tube. Just under 1 oz. Adjustment screw is also titanium. I was able to snatch these up last year.

Holy crap that’s light. Odd that they’re making an ultra light block but not offering .625

My BAD modified block is .39 oz, but only has one set screw.  Bet this one in .625 would be close.

I bought this gas block. The weight is a little optimistic according to my scale.



This is the GB that will be replaced and my scale matches the user entry for it.

If Us are to be believed, BAD is still the champ for GBs.

The spreadsheet needs some additions and revamping.

Anyone see these?

https://jlbillet.com/jl-billet-ar15-15-ultra-lite-angle-cut-m-lok-handguard/ < 8 oz

https://timbercreekoutdoorsinc.com/products/ul-e15-hg 8.8 oz with steel nut

Yeah, people move tabs around from time to time because they can. It's annoying, I'll fix it. Anything else an issue?

I don't know if Google Sheets has this (excel does) but implementing pivot tables from the tables would make searching for things so much easier, especially with slicers. Tap 15" Handguard and boom, that's all you see. Money.

I'm kind of an Excel guru of you need any help. It's to my understanding that Google sheets  a near 1:1 replacement to Excel. You should be able to lock the workbook from people moving tabs, adding tabs, etc. In Excel it's called protect workbook.

I have that Timber Creek handgaurd on a 4pound 16" gun, I like it a lot and they look sweet!  I think I posted picks of it in this thread a couple years back!

Superlative Arms now has their adjustable gas block in Raw or DLC Titanium in Set Screw or Clamp On.

I have a Next Intent Tactical/Master of Arms Ti adjustable gas block. It is awesome. However, on a recent range trip, I forgot to tighten the locking set screw on the side after adjusting. So, naturally I found the screw gone when I got back home. It probably walked out during the shooting. Anyone know what is the size of the side locking set screw? MOA website is gone and Next Intent doesn’t seem to deal with anything firearms anymore. So I’m here to see if anyone has this gas block can help me out. Thanks.

Jamming price on the DSA sand cut bcg...

https://www.dsarms.com/p-17128-dsa-ar15-enhanced-low-mass-aluminum-sand-cut-complete-bolt-carrier-group-556-223-300-blk.aspx?utm_source=BenchmarkEmail&utm_campaign=Black_Friday_2021&utm_medium=email

If you use code: BFCM25

You might be able to get the polymer lower from unbranded AR for 25% off. I haven't tried it, but it'd be a screaming deal on one of the cheapest/lightest lowers ever made.

 Got one on the way!  Thank you for posting this up, I really like these bcgs!  
 Happy Thanksgiving!

Looks like it works - knocks 3x down to just over under $30/per shipped.

JMT is a lower I would 100% trust for my AR builds, but is only 80%. I don't feel like I would trust the the Unbranded unless they are on .22lr or buffer less type uppers. I have 2 however.

Can't beat the price though.

Will throw em in a Vism thumbhole, probably give away one or two in the Let Every Man Be Armed 2.0 thread.

Who here has the lightest 20” build?

I know I have the lightest 27" build.  

Where can a person buy an aluminum grip screw without buying 20?  Thanks!

ETA, this is my current “lightweight” grip screw.

Uh, Home Depot?

@backbencher

Where are you finding them at Home Depot? I can’t find anything 1/4x28 at all.  Thanks!

I'm a Team member, so auto subscribed to the thread.  Please don't @ me in a thread I'm already in.

I went to the screw aisle, and dug through their little cabinets.  TrueValue probably has a better selection.

Thanks!

I don't post in here much, but people have been asking to access the spreadsheet, and I keep granting permission. Hopefully it isn't all jacked up.

Leitner-Wise Titanium Firing Pin

Definitely popcorn worthy.

Just an FYI, I'll be incorporating user data into the PWD soon. It's been on the back burner with my wife's cancer, so bear with me.